NN bonded polymers

Abstract

The extreme reactivity of hydrazine and its derivatives with oxidizers such as $HNO_3$ or $N_20_4$, leading to spontaneous ignition, has been utilized in developing self-igniting (hypergolic) propellant systems. Hydrazine, monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH) have long been used as fuels in biliquid rockets. For hybrid rocket propellants, solid fuels which ignite spontaneously on coming into contact with liquid oxidizers are preferred in order to give the motor onoff capability. Here again, solid derivatives of hydrazine or compounds with N-N bonds have been conceived as hypergolic fuels. Indeed, several of these compounds have very short ignition delays (the elapsed time preceding ignition after the liquid oxidizer and the solid fuel come in contact), with white or red fuming nitric acid (WFNA or RFNA) when used in the powder form.